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-rw-r--r--kernel/itimer.c4
-rw-r--r--kernel/posix-cpu-timers.c95
-rw-r--r--kernel/sched_stats.h45
3 files changed, 119 insertions, 25 deletions
diff --git a/kernel/itimer.c b/kernel/itimer.c
index 6a5fe93dd8bd..58762f7077ec 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -62,7 +62,7 @@ int do_getitimer(int which, struct itimerval *value)
struct task_cputime cputime;
cputime_t utime;
- thread_group_cputime(tsk, &cputime);
+ thread_group_cputimer(tsk, &cputime);
utime = cputime.utime;
if (cputime_le(cval, utime)) { /* about to fire */
cval = jiffies_to_cputime(1);
@@ -82,7 +82,7 @@ int do_getitimer(int which, struct itimerval *value)
struct task_cputime times;
cputime_t ptime;
- thread_group_cputime(tsk, &times);
+ thread_group_cputimer(tsk, &times);
ptime = cputime_add(times.utime, times.stime);
if (cputime_le(cval, ptime)) { /* about to fire */
cval = jiffies_to_cputime(1);
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index fa07da94d7be..db107c9bbc05 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -230,6 +230,37 @@ static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
return 0;
}
+void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
+{
+ struct sighand_struct *sighand;
+ struct signal_struct *sig;
+ struct task_struct *t;
+
+ *times = INIT_CPUTIME;
+
+ rcu_read_lock();
+ sighand = rcu_dereference(tsk->sighand);
+ if (!sighand)
+ goto out;
+
+ sig = tsk->signal;
+
+ t = tsk;
+ do {
+ times->utime = cputime_add(times->utime, t->utime);
+ times->stime = cputime_add(times->stime, t->stime);
+ times->sum_exec_runtime += t->se.sum_exec_runtime;
+
+ t = next_thread(t);
+ } while (t != tsk);
+
+ times->utime = cputime_add(times->utime, sig->utime);
+ times->stime = cputime_add(times->stime, sig->stime);
+ times->sum_exec_runtime += sig->sum_sched_runtime;
+out:
+ rcu_read_unlock();
+}
+
/*
* Sample a process (thread group) clock for the given group_leader task.
* Must be called with tasklist_lock held for reading.
@@ -476,6 +507,29 @@ static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
}
/*
+ * Enable the process wide cpu timer accounting.
+ *
+ * serialized using ->sighand->siglock
+ */
+static void start_process_timers(struct task_struct *tsk)
+{
+ tsk->signal->cputimer.running = 1;
+ barrier();
+}
+
+/*
+ * Release the process wide timer accounting -- timer stops ticking when
+ * nobody cares about it.
+ *
+ * serialized using ->sighand->siglock
+ */
+static void stop_process_timers(struct task_struct *tsk)
+{
+ tsk->signal->cputimer.running = 0;
+ barrier();
+}
+
+/*
* Insert the timer on the appropriate list before any timers that
* expire later. This must be called with the tasklist_lock held
* for reading, and interrupts disabled.
@@ -495,6 +549,9 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
BUG_ON(!irqs_disabled());
spin_lock(&p->sighand->siglock);
+ if (!CPUCLOCK_PERTHREAD(timer->it_clock))
+ start_process_timers(p);
+
listpos = head;
if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) {
list_for_each_entry(next, head, entry) {
@@ -987,13 +1044,15 @@ static void check_process_timers(struct task_struct *tsk,
sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY &&
list_empty(&timers[CPUCLOCK_VIRT]) &&
cputime_eq(sig->it_virt_expires, cputime_zero) &&
- list_empty(&timers[CPUCLOCK_SCHED]))
+ list_empty(&timers[CPUCLOCK_SCHED])) {
+ stop_process_timers(tsk);
return;
+ }
/*
* Collect the current process totals.
*/
- thread_group_cputime(tsk, &cputime);
+ thread_group_cputimer(tsk, &cputime);
utime = cputime.utime;
ptime = cputime_add(utime, cputime.stime);
sum_sched_runtime = cputime.sum_exec_runtime;
@@ -1259,7 +1318,7 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
if (!task_cputime_zero(&sig->cputime_expires)) {
struct task_cputime group_sample;
- thread_group_cputime(tsk, &group_sample);
+ thread_group_cputimer(tsk, &group_sample);
if (task_cputime_expired(&group_sample, &sig->cputime_expires))
return 1;
}
@@ -1329,6 +1388,33 @@ void run_posix_cpu_timers(struct task_struct *tsk)
}
/*
+ * Sample a process (thread group) timer for the given group_leader task.
+ * Must be called with tasklist_lock held for reading.
+ */
+static int cpu_timer_sample_group(const clockid_t which_clock,
+ struct task_struct *p,
+ union cpu_time_count *cpu)
+{
+ struct task_cputime cputime;
+
+ thread_group_cputimer(p, &cputime);
+ switch (CPUCLOCK_WHICH(which_clock)) {
+ default:
+ return -EINVAL;
+ case CPUCLOCK_PROF:
+ cpu->cpu = cputime_add(cputime.utime, cputime.stime);
+ break;
+ case CPUCLOCK_VIRT:
+ cpu->cpu = cputime.utime;
+ break;
+ case CPUCLOCK_SCHED:
+ cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p);
+ break;
+ }
+ return 0;
+}
+
+/*
* Set one of the process-wide special case CPU timers.
* The tsk->sighand->siglock must be held by the caller.
* The *newval argument is relative and we update it to be absolute, *oldval
@@ -1341,7 +1427,8 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
struct list_head *head;
BUG_ON(clock_idx == CPUCLOCK_SCHED);
- cpu_clock_sample_group(clock_idx, tsk, &now);
+ start_process_timers(tsk);
+ cpu_timer_sample_group(clock_idx, tsk, &now);
if (oldval) {
if (!cputime_eq(*oldval, cputime_zero)) {
diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index 8ab0cef8ecab..a8f93dd374e1 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -296,19 +296,21 @@ sched_info_switch(struct task_struct *prev, struct task_struct *next)
static inline void account_group_user_time(struct task_struct *tsk,
cputime_t cputime)
{
- struct task_cputime *times;
- struct signal_struct *sig;
+ struct thread_group_cputimer *cputimer;
/* tsk == current, ensure it is safe to use ->signal */
if (unlikely(tsk->exit_state))
return;
- sig = tsk->signal;
- times = &sig->cputime.totals;
+ cputimer = &tsk->signal->cputimer;
- spin_lock(&times->lock);
- times->utime = cputime_add(times->utime, cputime);
- spin_unlock(&times->lock);
+ if (!cputimer->running)
+ return;
+
+ spin_lock(&cputimer->lock);
+ cputimer->cputime.utime =
+ cputime_add(cputimer->cputime.utime, cputime);
+ spin_unlock(&cputimer->lock);
}
/**
@@ -324,19 +326,21 @@ static inline void account_group_user_time(struct task_struct *tsk,
static inline void account_group_system_time(struct task_struct *tsk,
cputime_t cputime)
{
- struct task_cputime *times;
- struct signal_struct *sig;
+ struct thread_group_cputimer *cputimer;
/* tsk == current, ensure it is safe to use ->signal */
if (unlikely(tsk->exit_state))
return;
- sig = tsk->signal;
- times = &sig->cputime.totals;
+ cputimer = &tsk->signal->cputimer;
+
+ if (!cputimer->running)
+ return;
- spin_lock(&times->lock);
- times->stime = cputime_add(times->stime, cputime);
- spin_unlock(&times->lock);
+ spin_lock(&cputimer->lock);
+ cputimer->cputime.stime =
+ cputime_add(cputimer->cputime.stime, cputime);
+ spin_unlock(&cputimer->lock);
}
/**
@@ -352,7 +356,7 @@ static inline void account_group_system_time(struct task_struct *tsk,
static inline void account_group_exec_runtime(struct task_struct *tsk,
unsigned long long ns)
{
- struct task_cputime *times;
+ struct thread_group_cputimer *cputimer;
struct signal_struct *sig;
sig = tsk->signal;
@@ -361,9 +365,12 @@ static inline void account_group_exec_runtime(struct task_struct *tsk,
if (unlikely(!sig))
return;
- times = &sig->cputime.totals;
+ cputimer = &sig->cputimer;
+
+ if (!cputimer->running)
+ return;
- spin_lock(&times->lock);
- times->sum_exec_runtime += ns;
- spin_unlock(&times->lock);
+ spin_lock(&cputimer->lock);
+ cputimer->cputime.sum_exec_runtime += ns;
+ spin_unlock(&cputimer->lock);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-04 13:54:18 +0000